Steam generator



G B. MADDOCKS. STEAM GENERATOR. APPLICATION FILED DEC.22, 1917 1,413,863. 7 Patented Apr. 25, 1922.

3 SHtETSSHEET FIQLZ. ,4R I I 34 I 64 Iza/vewior 660219015. Madd 0 oks.

GJB. MADDOCKS. STE-AM GENERATOR.

APPLICATION FILED DEC 22, I917 7 1,41 3,863. Patented Apr. 25, 1922.

' 3 SHEETS-SHEET 2.

Invcnior: I tieorge llMadigook/s. y

GfB. MADDOCKS. STEAM GENERATOR.

1 APPLICATION FILED DEC-22, I917.

1,41 3,63 Patented Apr. 25, 1922.

3 SHEETS-SHEET 3.

' Inn/i03 -48 a00z1geB.Maddoc7a.s

GEORGE nnnnnooks, or LLsron, MASSACHUSETTS.

STEAM GENERATOR.

Specification of Letters Patent. i Patgnted A131; H922,

Application filed December 22, 1917. Serial No. 208,358.

on the drawings representing like parts.

This invention relates to steam generators. The objects and features of the lnven tion will be best understood from the. following description, taken in connection with.

the accompanying drawings, ofa steam gen erator embodying one form of my invention and selected. for the "purpose of lllustration,

I it being understood that-the invention in its true scope is claims. V

In the drawings: Fig. 1 is a side elevation partly 1n. sectlon of a steam generator embodying one form of my invention;

definitely'set forth by the Fig.2 is a sectional detail'of one illustrative form of'blowbff which may beused in. said generator;

tion of the economizer;

Fig. 4 is a sectional detail of one form of scale-catching attachment which may be used with said generator;

Fig. 5 is a top plan vi w of the banks of generating tubes;

Fig. 6 is a sectional detail of one form of drum head r I Fig. 7 is a sectional detail of one formof junction box; and

Fig. 8 is a transverse section on line 8 8 of F 1, and showing the tubes of the front bank and the junction box arrangement upon'the left side of Fig. 1.

In the embodiment of the invention, herein disclosed there are fourteen banks of generating tubes, only seven of which, however, are shown for the sakeof simplicity, but it is to bev understood thatthe number of banks of generating tubes maybe varied accord ing to the size" of the generator. These banks of generating tubes are disposed in parallel vertical planes, the upper tube 2 of each bank communicating with the water drum 4 by a tube 6, and the lower tube 8 cat.

each bank communicating with the steam drum 5, by a tube 10. As all of said banks junction-box 14, with which also communicates the left endof another generating tube 16, the right I end of which communicates with a junction-box 18. Another generating tube 20, Fig. 5, on the same level as the generating tube 16, communicates at its right end with the junction-box l8, and at its left end'with a junction boi-22,Fig; 5, located behind the junction-130x14 and withwhich communicates the left end of another generating tub'e 23, 'Fig. 8,, located below the generatlng-tube 2O and'in the same'vertical plane as the latter,- and communicating with,

its right end with 'a'junctio'n-box 24, Fig; 1.

with this junction-box 24 communicates the a right end ofa generating tube 26 located be crating tube 26 communicates with a junc;

tio nbox 28, with which communicates the left endiot another fgen erating tube 30 located below and in: the samevertical plane. as the generatlng tube 26, and having its right end communicating with a.-junction- 'box32. With thisj'unction-bon32 commulow and in theisameverticalplane as the I generating tube 16. The leftend of the gen Fig. 8 is a top plan View showing a'por-.

nicates the right'end' of another generating tube 3l,Fig. 8, and having its left end com inunicating with ajuncti'on-box 34*located behind the junction-box 28, see Fig. 8, and with which communicates thelett end of another genera-tingtube 36 locatedbelow' and in the same vertical plane-as the generating tube 3lg The-right end of this generating tube 36 communicates, with: a unctionbox 38, with Whichalso communicates the right end of a generating tube 40*located. in-the same vertical plane as the generating tube :80 and communicating at its left'cnd with a junction-box 42.; With this junction-box 42 communicates the left end of another generatingtube 44, the rightend of which'communicates with a junction-box 46. With this junction-box 46cominunicates t-heright end of anothergenerat ngtube located in the same vertical plane of, the, generating tube 36, and havi-ngfi-ts end; commuliiq eating with a iunction-box '50 locatedbehind the junction-box 42, see Fig. 8. With thls junction-box 50 communicates the left end of a generating tube 52, located in the same vertical plane as the generating tube 48 and communicating at its right end with the junction-box 5e. /Viththis junction-box 54h communicates the right end of the lower tube 8 of said bank. 'This tube 8 is located in the same vertical planeas the tube 44: and communicates at its'left end with a unctionbox 56 from which the tube 10 above referred toleads upwardly to a junction-box 58, Fig. 1, which communicates by a tube with the steam drum 5 at the side of the latter. 7

As above stated, the other banks of. junction-boxes are similar in construction and arrangement to that justdescribed, the pipe 10 communicating with the steam drum 5 through a junction-box and pipe located in the same verticalplane as the junction-box 58 and. pipe 60 of the first bank of generating tubes. In the same manner the pipes 6, lead ing from the water drum to the first generating tube of each bank, are located in the same vertical plane.

It will .be noted that by the arrangement described of the junction-boxes for the generating tubes, said generating tubes are all disposed horizontally, with the exception of the lowest tube 8 of each bank, which are inclined upwardly .toward their left ends, Fig. 1, thereby insuring that the tube 10 shall be free from water.

The economizer through which the water is fed into the water drum herein comprises four horizontal banks of tubes 61, but it is to'be understood that the number of said banks, and the number of tubes composing the same, may be varied according to the size of the generator. The tubesof each bank communicate each with the next adjacent one, and the last tube of each bank with the first tube of thebanlr on the next level,by

means of j auction-boxes 63, in such manner that the water, entering the economlzer by the p1pe 62 from a suitable source of supply,

will circulate through the several banks of.

tubes successivelyfrom the uppermost bank to the lowermost one and enter the water drum through the pipe 64; leading thereto from the lowermost bank. A pump of any usual and suitable construction, and driven from any suitable source ofpower, may be used to pump the water from'the source of supply, through the econom'izer into the water drum. V

The junction-boxes will preferably all be similar in construction. In the embodiment of the invention herein disclosed the tubes communicating therewith have their ends expanded and flared into said box. To this end, as shown in 7, circular openings a e previrledil th ell the j n ti nbox opposite that through which the tubes enter, said openings 68 having their inner edges bevelled and closed by plugs 70, having bevelled edged end portions 72, fitting the bevelled edges of said opening. Said plugs are provided with shanks 74 extending through openings provided in yokes 7 6 projecting from the junction-box, the free ends of said shanks being screw-threaded to receive nuts 77 whereby said plugs may be clamped securely in place.

It is to be noted that the steam and water drums and junction-boxes of the economizer tube and generating tubes are protected from the direct heat of the fire-box and setting, said drums being, in the embodiment of the invention herein shown, located above the top'firebrick wall 66 of the generator setting, and said junction-boxes outside of the vertical firebrickwalls 78, 80, and S2of the set ting. This enables said drums and unctionboxes to be made of a thickness to withstand very high pressure, the generator of my invention being intended to furnish. a pressure of 800 pounds and over. To this end said junction-boxes and drums will preferablybe made of relatively thick steel castings. thickness of 3?; inches has been found adequate for the drum walls,

The invention also contemplates the pro vision of means to prevent the entrance of scale or other foreign matter with the water used in the generator, said means herein comprising a scale-catching attachment through which the water passes before entering the tube .62 of the economizer. Said scale-catching attachment may be of any suitable construction, and in the embodiment thereof herein shown comprises a receptacle 84 closed at the top by a cover 86 bolted to a flange 88 extending'around the upper edge of said receptacle, by means of bolts 90. Said receptacle is provided with a central partition 92 extending downwardly approximately twothirds of the depth of said receptacle, the water from the supply entering said receptacle at one side of said partition through a pipe 94 and passing out of said receptacle through an opening provided in the wall of said receptacle, at the opposite side of said partition from the tube 94, into which opening the end of the'tube 62 is threaded or otherwise firmly secured. In this way, any scale or other foreign solid matter, entering said receptacle 84, will be arrested by the partition 92 and, falling to the bottomof said'receptacle, will settle there. A pipe 96 is herein shown as tapped into the bottom of said receptacle and provided with a valve 98 by opening which the scale that has col lected from time to time may be removed.

'My invention also contemplates a novel drum and drumhead construction, avoiding the use of rivets and seams, which are the weakestlpart or i drum,owing to theirforming a lodging place for scale, as will be readknown to need further description.

ily understood by those skilled in the art, the drums being preferably cast in a single piece, for this purpose. In the embodiment of the invention herein disclosed the drum heads 100, one of which is shown in detail in Fig. 6, are mounted to swing open and shut. To this end the drum head is provided with an ear 102 which is embraced between two cars 104, provided at the end of the drum proper, a pin 106 fitting through openings provided in said ears 102, 104 to act as a pivot. The end face of the drum is provided with an annular groove 108, within which fits an annular tongue or rib 110 upon the inner face of the drum head, when said drum head i closed. To secure said drum head in closed position, any suitable means may be provided, said means herein consisting of bolts 112 extending through openings 114 suitably spaced around said head and registering with screw-threaded openings 116 provided in the end face of the drum and into which said bolts are screwed securely to fasten the head in place. 7

Equalizing pipes are preferably provided connecting the two drums. Herein four such pipes are provided, communicating, on the one hand; with openings suitably spaced one side of the steam drum 5, and, on the other hand with an equal number of openings suitably spaced along. the top of the water drum 4. One of-said pipes is shown at 118 in Fig. 1. Each of said pipes will preferably be provided'with a checkvalve 120, opening toward the water drum. These check-valves may be of any suitable and usual construction and are too well- These check-valves, as will be readily understood by those skilled in the art, will be preferably constructed and arranged to be normally closed and will of course remain closed while the boiler isin operation, but may openwhen the boiler has no load.

A by-pass 122 will preferably be provided between toe drum 4 and tube 62 of the economizer and a check-valve 124, opening downwardly, will preferably be provided in said by-pass. This check-valve, like the others above referred to, may be of any suitable and usual construction'and need not be herei more particularly described.

Preferably also, means will be provided to drain offany water-of condensation that may be formed in the steam drum, and to that end, in the above'invention herein disclosed, two drainage pipes 125, 125 are provided, saiddrainage pipes communicating on the one hand with openings suitably spaced in the bottom of the steam drum 5, and on the other hand with the junction-boxes, re spectively, of the tubes 2 of two of the banks of generator tubes. Each drainage pipe 125 and suitable construction and-neednot be more specifically described.

The invention further contemplates the provision of a separate blow-off for each bank of generating tubes, said blow-off being located in the right-hand end, viewing Fig. 1, of the lowest tube 8 of each of the generating tube banks. Said blow-ofl may be of any suitable construction, and in the illustrative embodiment of the invention herein shown comprises a rotary valve 126, see Fig. 2, connected on the one hand by apipe 128 with the base of the junction-box 54 into which the generating tube 8 opens, and on the other hand by a pipe 130, with a main drain pipe 132 extending along the front of the generator on a level with the junction-boxes of the lower tubes 8 of all of the generating tube banksn All of the blow-offs communicate with this waste pipe, thus affording convenient means for blowing off each bank of tubes separately, so; as to be sure that each bank is clear;

My generator will also preferably be pro vided with a water gauge;'said gauge being herein shown at 134 and being provided with suitable windows 136 of glass or other transparent material, through, which the height the steam drum, to prevent waterpassing over into the steam drum through the pipe 140, in case of a sudden demand for steam on the drum. This gauge also may be of any suitable and well-known construction and need not be described more fully herein. A discharge-pipe 144,'provided with a valve 146, communicates with the drum 4 and gauge 134.

The generator comprises the usual baffies 148, herein threesuch bafiies being provided, but it will be apparent that the number of baffles used may vary with the number of tubes contained. in. the generator'tube banks.

The drums 4 and 5 are supported bya plurality of supporting yokes 150, only .one of which for each drum is herein shown, said yokes being supported-by supporting'mem I are fed through doors 166. .Severalsuch.

opening toward the gauge andpaway from doors 1166 will be provided,as usual, upon either side. also provided upon eithersid e for withdrawing the ashes.

It is believed that the operation of my generator will be clear to those skilled in the art, from thedescription of the. generator A plurality of doors 168 are above given, and that therefore no separate detailed description of the operation will be necessary.

It will be seen that the water, passing downwardly by gravity from the water drum 4 through the banks of generator tubes, passes successively through zones of increasing heat from the less heated to the hottest, the water in this transition being thus first converted into steam and the latter in passing through the hottest zone being superheated before ascending to the steam drum.

In accordance with my invention, the water and steam are in separate drums, and the water in the water drum does not come in contact with the steam in the steam drum. As a result, the temperature of the steam in the steam drum is quite independent of and unaiiected by the temperature of the water in the water drum. Itis thus unnecessary to heat the water drum and steam drum with the flue gases, the water being heated and steam being generated in the banks 0]": generator tubes. The fiue gases for these reasons can be, and in the generator of my invention are, sent out at a lower temperature than that or": the steam, thus greatly economizing iiuel. Furthermore, this enables both drums to be located outside the firing zone or setting, and the steam drum can thus be made of metal of a thickness sufiicient to withstand great pressure, 1,000 lbs. pres sure, or even more being possible in a generator constructed in accordance with my invention. It is thus possible to develop an enormous horsepower in a relatively small space and with great economy in fuel, etc. In like manner the junction-boxes and tube ends are protected from the action of the fire, being herein for that purpose located outside of the fire zone or setting, and so can be made of a thickness sufiicient to withstand the highest pressure.

The separate blow-oils for each bank of generatortubes enable each bank to be blown separately, so that one can always be sure that each bank is clear.

By the provision of means to tree the water entering the generator from scale, herein exemplified in the scale-catching attachment. described, the entrance with the water of scale, or other solid matter, into the system is prevented.

, Another advantage possessed by my invention resides in'the provision of means, herein exemplified by the check-valves described, to prevent water from passing from the water drum through the equalizing tubes into the steam drum, forcing the water into the generating tubes, thereby improving the circulation. V

The drum head construction herein described also possesses advantages over those heretofore used, that will be obvious to those skilled in the art.

@ther advantages resulting from my described invention, in addition to those pointed out above, will appear to those skilled-in. I

' Obviously it is not indispensable that all the art.

oi the features of my invention be used conjointly, since they may be used to advantage separately in various combinations and subcombinations. It will also be apparent that, while the invention is herein described as embodied in the details illustrated, the invention isnot to be considered as circumscribed by or limited to thesev details, or any one of them, but that said details may be. variously modified within the true scope of the invention, which is definitely set forth by the claims.

Having now described one specific embodiment of my invention, what I claim, and desire to secure by Letters Patent, is

1. In a steam generator, in combination, a water drum; a steam drum; one or more equalizing tubes connecting said drums; means to prevent the passage of water through said equalizing tube or tubes from the water drum into the steam drum; an economiserifior supplying said water drum with water; a setting; one or more banks of generator tubes, the tubes whereof extend through said setting, the upper tube of said bank or banks of generator tubes being connected to the water drum, and the lower tube of said bank or banks of generator tubes being connected to the steam drum; and junction-boxes for the tubes of said economizer and for the'generator tubes, said' junction-boxes and said water drum and steam drum being located outside the walls of said setting.

2. In a steam generator, in combination, a water drum; a steam drum; one or more tubes connecting said drums; means to prevent communication through said tube or tubes from the water drum to the steam drum, but permitting communication there through from the steam drum to the water drum; an economizer tor supplying said water drum with water; a setting; one or more banks of generator tubes, the tubes whereof extend through said setting, the upper tube of said bank orbanks of generator tubes being connected to the water drum, and the lower tube of said bank or banks of generator tubes being connected to the s eam drum; and unction-boxes for the tubes of said economizer and forv the generator tubes, said junction-boxes and said water drum and 'steam drum being protected from the fire'in said setting.

In testimony whereof, I have signed my name to this specification.

GEORGE B. MADDUGKS. 

